Extraction of β‐galactosidase from Saccharomyces fragilisIZ 275 grown in cheese whey

Abstract

BACKGROUND The enzyme β‐galactosidase (EC 3.2.1.2.3) obtained from yeast is produced intracellularly. Cell extraction consists of the treatment of a cell suspension with chemical agents, thus obtaining the enzyme with biological activity. After obtaining the extracted enzyme, it is concentrated by ultrafiltration and dried. Lyophilization can be used in this step. The objective of this work was to study the production and extraction of β‐galactosidase from Saccharomyces fragilis IZ 275 using lactose from cheese whey. RESULTS Under optimum extraction conditions, 2% (v/v) chloroform, 37 °C for 6 h of extraction, 35% of lactose hydrolysis was achieved using 1% (v/v) β‐galactosidase during 10 h of hydrolysis. Extracted enzyme activity resulted in 81% lactose hydrolysis using 12% (v/v) enzyme at pH 6.0 and 37 °C. Enzymatic kinetics were evaluated using 12% of extracted enzyme in 5 h of hydrolysis reaction, and 100% lactose hydrolysis was obtained. The enzyme activity after extraction, concentration and lyophilization was 100%, 60% and 45.3% of lactose hydrolysis, respectively, after 5 h of hydrolysis reaction at 37 °C and pH 6.0. CONCLUSION The yeast S. fragilis IZ 275 grown in cheese whey produces intracellular β‐galactosidase and its extraction is efficient with the use of 2% chloroform at 37 °C for 6 h, allowing its use for industrial and pharmaceutical purposes. The extracted enzyme must be used at 37 °C and pH 6.0 at a concentration of 12% (v/v) of enzyme to obtain the total hydrolysis of lactose in 5 h of reaction. © 2022 Society of Chemical Industry (SCI).